Process for protecting a substrate with an arylsulfonemidopyrimidine intumescent agent

ABSTRACT

Intumescent compositions of the invention comprise certain arylsulfonamidopyrimidines, such as the 2-, 4-, and 5sulfanilamidopyrimidines. The intumescent agents may be employed in conjunction with additives conventionally used in intumescent compositions. For use in protecting substrates from heat and fire, the intumescent compositions may be applied to the substrate in any suitable manner, such as by electro-deposition, spraying onto an adhesive substrate, or application of a coating composition comprising the intumescent agent.

as: st'lastmfv v a SEARCH ROOM w F l 1 5'5 United stat [111 swam? Roth 1Oct. 335 1973 1541 PROCESS FOR PRQTECTINEUB SUBSTRATE WITH AN PrimaryExaminer-William D. Martin ARYLSULFONEMIDOPYRIMIDINE AssistantExaminer-Harry J. Gwinnell INTUMESCENT AGENT AttorneyRichard S.Strickler, Elton F. Gunn, Pa- 0 tricia J. Hogan, Burton E. Levin, JoshuaJ. Ward. Ed- 1 inventor: shrley Roth Hghland Park win T. Yates, GeorgeL. Rushton and A. Joe Reinert [73] Assignee: Cities Service Company, NewYork,

[22] Filed: Feb. 11, 1972 [57] ABSTRACT [21] Appl. No.: 225,638

lntumescent compositions of the invention comprise certainarylsulfonamidopyrimidines, such as the 2-, 4-,

2% and 5-sulfanilamidopyrimidines. The intumescent W 106,15 FF agentsmay be employed in conjunction with additives K l 1 o can:conventionally used in intumescent compositions. For

252/8'l use in protecting substrates from heat and fire, the in- 't/13:3; tumescent compositions may be applied to the sub- [56] ReferencesCited strate in any suitable manner, such as by electro- UNITED STATESPATENTS deposition, spraying onto an adhesive substrate, or ap-3,535,130 10/1970 Webb 117/136 X plication of a coating'compositioncomprising the im 3 a 3,663,464 5/1 72 SZiWkO.... 117/136 X tumescentagent J 3,707,554 12/1972 Hardy 117/136 X OTHER PUBLlCATlONS 6 Claims NoDrawings Northey, Sulfonamides," p. 31, Table 28 (1948).

1 PROCESS FOR PROTECTING A SUBSTRATE WITH AN ARYLSULFONEMIDOPYRIMIDINEINTUMESCENT AGENT BACKGROUND OF THE INVENTION 1. Field of the InventionThis invention relates to intumescent compositions and more particularlyrelates to such compositions containing a one-component intumescentagent.

2. Description of the Prior Art It is known that a substrate may beprotected from heat and tire by the application of an intumescentcomposition. lntumescent compositions of the prior art usu ally containan intumescent agent having at least three components; i.e., acarbonific, a spumitic, and a catalyst; and they are typicallycharacterized by the disadvantages of high cost, low spreading rate,relatively poor efficiency, poor water resistance, and poorweatherability.

As disclosed in U. S. Pat. No. 3,535,130, it has already been discoveredthat a one-component intumescent agent has advantages overmulticomponent intumescent agents. However, the intumescent agents ofthe patent have poor adherence to substrates and have an undesirabledegree of moisture sensitivity.

SUMMARY OF THE INVENTION An object of this invention is to provide anovel class of one-component intumescent agents.

Another object is to provide such intumescent agents having goodefficiency and a low level of moisture sensitivity.

These and other objects are attained by using as intumescent agentscompounds corresponding to the formula:

wherein Ar is a divalent aromatic residue, R is hydrogen, hydrocarbon,halohydrocarbon, or acyl, and R" is a pyrimidyl or substituted pyrimidylradical.

DESCRIPTION OF THE PREFERRED EMBODIMENTS contain 1-5 carbon atoms. Whenthere are halo substituents, it is usually preferred that they be chloroor bromo. lt is also preferred that the aromatic ring have at least onefree reactive position.

As indicated above, R of the formula may be hydrogen or a hydrocarbon,halohydrocarbon, or acyl radical, i.e., an alkyl, chloroalkyl, orbromoalkyl radical containing l-5 carbon atoms, a phenyl, chlorophenyl,or bromophenyl radical, or an aliphatic or aromatic acyl radical.

R" is preferably a pyrimidyl radical, but it may bear one or moresubstituents if desired. The substituted pyrimidyl radicals mostcommonly found in these compounds are the chloro, bromo, carboxy,hydroxy, amino, thio, sulfonamido, C C,, alkyl, C,C alkoxy, phenyl, andbenzo derivatives, but compounds containing other substituted pyrimidylradicals are also utilizable. When R" is a substituted pyrimidylradical, the nitrogen of the sulfonamide group may be attached directlyto the pyrimidine ring, or it may be attached to the pyrimidine ringthrough the substituent.

Exemplary of the intumescent agents of the invention are2-sulfanilamidopyrimidine, 4- sulfanilamidopyrimidine,5-sulfanilamidopyrimidine.2-(4-amino-3-chlorobenzenesulfonamido)pyrimidine,2-(2-amino-4-bromobenzenesulfonamido)pyrimidine,2-(4-amino-2-ethylbenzenesulfonamido)pyrimidine,2-(3-amino-4-chloromethylbenzenesulfonamido)- pyrimidine,2-(4-amino-2-butoxybenzenesulfonamido)pyrimidine, 2-(4-amino'3-chloromethoxybenzenesulfonamido)pyrimidine, 2-(4-amino-3-carboxybenzenesulfonamido)pyrimidine, 2-(3,4-diaminobenzenesulfonamido)pyrimidine, 2-(4-amino-2-acetamidobenzenesulfonamido)pyrimidine,2-(2-amino-4-nitrobenzenesulfonamido)pyrimidine,2-(4-methylaminobenzenesulfonamido)-pyrimidine,2-(4-chloroethylaminobenzenesulfonamido)- pyrimidine,2-(4-bromoethylaminobenzenesulfonamido-pyrimidine,2,-(4-phenylamin0benzenesulfonamido)-pyrimidine,2l4-(pchlorophcnylumino)benzcnesulfonamidolpyrimidine,2-[4-(p-bromophcnylamino)bcnzenesulfonamido pyrimidine,2-(p-acetamidobenzenesulfonamido)- pyrimidine, 2-(p-benzamidobenzenesulfonamido pyrimidine,5-chloro-2-sulfanilamidopyrimidine, 5-bromo-4,6-dimethyl-2-sulfanilamidopyrimidine, 4-

ethylcarboxy-Z-sulfanilamidopyrimidine, 4-hydroxy-2-sulfanilamidopyrimidine, 2- suIfanilamidoaminopyrimidine, 2-amino-5-sulfanilamidopyrimidine, 4-diethylamino-2- sulfanilamidopyrimidine,2-ethylthio-4- sulfanilamidopyrimidine, 2-(4- aminophenylsulfonamido)-5-sulfanilamidopyrimidine, 4-methyl-2sulfanilamidopyrimidine,5-butyl-2- sulfanilamidopyrimidine, 4,6-dimethyl-2-sulfanilamidopyrimidine, 2-methoxy-5- sulfanilamidopyrimidine,4-phenyl-2- sulfanilamidopyrimidine, 2- sulfanilamidobenzopyrimidine,the corresponding naphthalene compounds, etc. When not readilyavailable, these compounds may be prepared by known techniques.

For use in protecting a substrate from heat and fire, the intumescentagents of the invention may be applied in any suitable manner, e.g.,electrodeposition, spraying of powdered intumescent agent onto anadhesive substate, etc. However, it is usually preferred to compound theintumescent agent with a binder, e.g., nitrocellulose, and optionallyalso with one or more of the other ingredients conventionally used inintumescent eompositons, e.g., stabilizers, dispersing agents, pigments,driers, biocides, anti-foamers, thickeners, protective colloids,fillers, blowing agents, etc.; disperse the composition in a suitableliquid medium, e.g., water or a solvent or solvent mixture; and applythe coating composition thus formed to the substrate to be protected. Asis the case with conventional intumescent coating compositions, it isfrequently convenient to apply these coating compositions in the form ofa paint having a solids content of about -70 percent by weight and ani'ntumescent agent/binder weight ratio of EXAMPLE I Place one gram of2-sulfanilamidopyrimidine in an aluminum pan and flame it with a propanetorch. The compound intumesces to form an excellent volume of foamhaving a good cell structure.

Similar results are also observed when 4- and 5-sulfanilamidopyrimidines and the other intumescent agents mentioned inthe specification are substituted for the intumescent agent of theExample.

It is obvious that many variations may be made in the products andprocesses set forth above without departing from the spirit and scope ofthis invention.

What is claimed is:

1. A process for protecting a substrate from heat and fire whichcomprises applying thereto an intumescent composition comprising as theintumescent agent a compound corresponding to the formula:

wherein Ar is a divalent aromatic residue, R is hydrogen, hydrocarbon,halohydrocarbon, or acyl, and R is a pyrimidyl or substituted pyrimidylradical.

2. The process of claim 1 wherein Ar is a divalent aromatic residuederived from benzene or naphthalene or an alkyl, haloalkyl, alkoxy,haloalkoxy, halo, hydroxy,

agent is 5-sulfanilamidopyrimidine. =2:

Po-ww UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,769,077 Dated OCtObGILBO, 1973 Invent0r( )jhj Nev H. Roth It iscertified that error appears in' the above identifi I ed ate t and thatsaid Letters Patent are hereby corrected as shown below n Emumn 1, lines36 41, and commn 4, mes 4 9 th portion of the formu1a reading NHRQIIshould read --NHR" Signed and sealed this 13th day of August 197 (SEAL)Attest:

MCCOY M. GIBSON, JR. Attesting Officer C. MARSHALL DANN Commissioner ofPatents

2. The process of claim 1 wherein Ar is a divalent aromatic residuederived from benzene or naphthalene or an alkyl, haloalkyl, alkoxy,haloalkoxy, halo, hydroxy, carboxy, amino, amido, or nitro derivativethereof.
 3. The process of claim 1 wherein R'''' is a pyrimidyl radicalor a halo, carboxy, hydroxy, amino, thio, sulfonamido, alkyl, alkoxy,phenyl, or benzo derivative thereof.
 4. The process of claim 1 whereinthe intumescent agent is 2-sulfanilamidopyrimidine.
 5. The process ofclaim 1 wherein the intumescent agent is 4-sulfanilamidopyrimidine. 6.The process of claim 1 wherein the intumescent agent is5-sulfanilamidopyrimidine.